sample start script template

start.sh

#!/bin/bash
PNAME="tail"
PNAMEFULL="Tail"
PPATH="${HOME}"
PBIN="tail -f /var/log/dmesg.log"

PLOG="${PPATH}/${PNAME}.log"
PIDPATH="${PPATH}/${PNAME}.pid"

USESCREEN=0
SCREENNAME="${PNAME}-${$}"

check-running() {
  if [ -f "${PIDPATH}" ]; then
    return 0
  else
    return 255
  fi;
}

case ${1} in
  start)
    check-running
    if [ ${?} -eq 0 ]; then
      echo "${PNAMEFULL} is still running!"
      echo "May you need to delete '${PIDPATH}'?"
      exit 2
    fi
    echo -n "Starting ${PNAMEFULL}... "
    case ${USESCREEN} in
      1)
        screen -AmdS "${SCREENNAME}" "/bin/bash -c '${PBIN} 2>&1 | tee -a ${PLOG}'"
        screen -list | grep "${SCREENNAME}" | sed -n -r 's/\w([0-9]+).*/\1/p' > "${PIDPATH}"
        echo -e "\e[00;32mdone!\e[00m"
        ;;
      0)
        nohup /bin/bash -c "${PBIN}"' 2>&1 | tee -a '"${PLOG}" 2> /dev/null &
        echo ${!} > "${PIDPATH}"
        echo -e "\e[00;32mdone!\e[00m"
        ;;
    esac
    ;;
  stop)
    check-running
    if [ ${?} -gt 0 ]; then
      echo "${PNAMEFULL} is not running!"
    else
      echo -n "Stopping ${PNAMEFULL}... "
      PADPID=$(cat "${PIDPATH}")
      if [ "${PADPID}" ]; then
        case ${USESCREEN} in
          1)
            screen -S "${PADPID}" -X quit
            if [ ${?} -gt 0 ]; then
              echo -e "\e[00;31mfailed!\e[00m"
              exit 255
            fi
            ;;
          0)
            kill "${PADPID}"
            if [ ${?} -gt 0 ]; then
              echo -e "\e[00;31mfailed!\e[00m"
              exit 255
            fi
            ;;
        esac
      else
        echo -e "\e[00;31mfailed!\e[00m"
        exit 255
      fi
      rm "${PIDPATH}"
      echo -e "\e[00;32mdone\e[00m"
    fi
    ;;
  restart)
    ${0} stop
    sleep 1
    ${0} start
    ;;
  status)
    check-running
    if [ ${?} -gt 0 ]; then
      echo "${PNAMEFULL} is not running!"
    else
      echo "${PNAMEFULL} is running!"
    fi
    ;;
  statuscode)
    check-running
    echo ${?}
    ;;
  *)
    echo "Usage: "${0}" {start|stop|restart|status|statuscode}"
esac